1. Field of the Invention
The present invention relates to video game machines using a recording medium such as an optical disk, a magnetic disk, or a semiconductor memory in which program data are recorded, methods for switching a viewpoint on a game screen of a video game, and recording media containing a program for switching the viewpoint on the game screen of the video game.
2. Description of the Related Art
Many game systems have been proposed, such as a system comprised of a home-use game console and a television monitor, a commercial-use game machine, and a system comprised of a personal computer or work station, a display, and a sound output device.
The game systems each include a player-operated controller, a recording medium containing game-program data, a central processing unit (CPU) for performing control for the generation of sound and images based on the game-program data, a processor for generating images, a processor for generating sound, a monitor for displaying images, and a speaker for outputting the generated sound. In many cases, the types of recording medium include a compact-disk readonly memory (CD-ROM), a semiconductor memory, and a cassette having a built-in semiconductor memory.
In the game systems, a model or character as each object displayed on the monitor is, in general, three-dimensional formed by a plurality of polygons that are two-dimensional virtual triangles or quadrangles. By pasting textures as two-dimensional-image data on the polygons, the model or character is displayed as a three-dimensional image.
In the game systems, the number of viewpoints used when a game screen including three-dimensional images is displayed on the monitor is normally set to one. In the case where the monitor screen is divided into portions for displaying a plurality of game screens, while using a plurality of viewpoints, the size of each game screen is reduced. This reduction in the game screen reduces the dynamism of the game. The use of one viewpoint prevents this problem from occurring.
Conventional video games are known in which a plurality of leading characters appear and are designed to be operated by corresponding players.
Also in these video games in which the leading characters appear, the number of viewpoints is set to one. Thus, it is difficult for each player to appropriately grasp the relationship between each operation status and the corresponding leading character.
Accordingly, the present invention has been made in view of the foregoing circumstances. It is an object of the present invention to provide a video game machine in which viewpoints used when a game screen is displayed on a monitor are set so as to correspond to a plurality of leading characters and the viewpoint is switched from one to another, a method for switching a viewpoint on a game screen of a video game, and a computer-readable recording medium containing a program for switching a viewpoint on a game screen.
To this end, according to an aspect of the present invention, the foregoing object is achieved through provision of a video game machine including: a plurality of operation units, which correspond to a plurality of leading characters appearing in a virtual three-dimensional space, causing the corresponding leading characters to move; a game-screen display unit; a coordinate storage unit for storing pairs of coordinates set so as to be related to the leading characters; a game-screen display-control unit for displaying, on the game-screen display unit, a game screen obtained by using, as a viewpoint, any one of the pairs of coordinates; an operation determination unit for determining whether a viewpoint-switching operation has been implemented among operations using one operation unit for moving one leading character related to the pair of coordinates of the viewpoint in the game screen displayed on the game-screen display unit; and a viewpoint-switching-display control unit for initiating a viewpoint-switching movement of switching the pair of coordinates of the viewpoint to another pair of coordinates when the operation determination unit has determined that the viewpoint-switching operation has been implemented.
Preferably, when the operation determination unit has determined that the viewpoint-switching operation has been implemented, the viewpoint-switching-display control unit displays, on the game-screen display unit, a viewpoint-switching item as the viewpoint-switching movement.
The video game machine may further include a prohibition-control unit in which while the viewpoint-switching item is being displayed, the prohibition-control unit prohibits the operation determination unit from determining whether the viewpoint-switching operation has been implemented.
The operation determination unit may determine one leading character specified by the viewpoint-switching operation from among the other leading characters displayed on the game-screen display unit.
The operation determination unit may further determine whether a viewpoint-switching rejecting operation has been implemented among operations using one operation unit corresponding to the specified leading character. When the operation determination unit has determined that the viewpoint-switching rejecting operation has been implemented, the viewpoint-switching-display control unit may interrupt the viewpoint-switching movement and may terminate the display of the viewpoint-switching item, while when the operation determination unit has determined that no viewpoint-switching rejecting operation has been implemented, the viewpoint-switching-display control unit may switch the pair of coordinates of the viewpoint to a pair of coordinates set so as to be related to another leading character, and may terminate the display of the viewpoint-switching item.
The viewpoint-switching-display control unit may move the viewpoint-switching item being displayed toward the specified leading character, and when the operation unit corresponding to the specified leading character is operated for attacking or avoiding the viewpoint-switching item, the operation determination unit may determine that the viewpoint-switching rejecting operation has been implemented.
The viewpoint-switching-display control unit may move the viewpoint-switching item being displayed toward the specified leading character, and when the operation unit corresponding to the specified leading character is not operated for attacking or avoiding the viewpoint-switching item, and the viewpoint-switching item reaches a predetermined range including the specified leading character, the operation determination unit may determine that the viewpoint-switching rejecting operation has not been implemented.
The viewpoint-switching-display control unit may move the viewpoint-switching item being displayed toward the specified leading character, and when the operation unit corresponding to the specified leading character is not operated for attacking or avoiding the viewpoint-switching item, and the viewpoint-switching item reaches a predetermined range including the specified leading character, the operation determination unit may determine that the viewpoint-switching rejecting operation has not been implemented.
According to another aspect of the present invention, the foregoing object is achieved through provision of a method for switching a game-screen viewpoint used in a video game displaying, on a game-screen display unit, a game screen on which a plurality of leading characters appearing in a virtual three-dimensional space are moved by using operation units corresponding to the leading characters and on which any one of a plurality of pairs of coordinates related to the leading characters is used as a viewpoint. The method includes the steps of determining whether a viewpoint-switching operation has been implemented by using one of the operation unit so that one of the leading characters which is related to the pair of coordinates of the viewpoint for the game screen displayed on the game-screen display unit, and initiating a viewpoint-switching movement for switching the pair of coordinates of the viewpoint to another pair among the pairs of coordinates when it is determined that the viewpoint-switching operation has been implemented.
According to a further aspect of the present invention, the foregoing object is achieved through provision of a computer-readable recording medium containing a game-screen-viewpoint switching program for a video game displaying, on a game-screen display unit, a game screen on which a plurality of leading characters appearing in a virtual three-dimensional space are moved by operation units corresponding to the leading characters and on which any one of a plurality of pairs of coordinates related to the leading characters is used as a viewpoint. The game-screen-viewpoint switching program includes a determination step for determining whether a viewpoint-switching operation has been implemented by using one of the operation unit so that one of the leading characters which is related to the pair of coordinates of the viewpoint for the game screen displayed on the game-screen display unit, and a viewpoint-switching-movement initiating step for initiating a viewpoint-switching movement for switching the pair of coordinates of the viewpoint to another pair among the pairs of coordinates when it is determined that the viewpoint-switching operation has been implemented.
According to the present invention, each player operating the operation unit corresponding to each leading character can clearly grasp the relationship between each operation status and the movement of the leading character. A viewpoint-switching movement, which is being performed, can be clearly displayed for the player operating each leading character. A viewpoint for a game screen displayed on a game-screen display unit can be preferably switched among pairs of coordinates set to be related to leading characters. Viewpoint switching can be securely performed. The player, operating each operation unit corresponding to a specified leading character, can select acceptance or rejection of viewpoint switching, which enhances the enjoyment of the game. A viewpoint-switching rejecting operation can be clearly indicated. No implementation of a viewpoint-switching rejecting operation can be clearly indicated. The execution of viewpoint switching can be clearly indicated, which can express the dynamism of viewpoint switching.